Money man had a tumultuous summer in 2007, but flagship fund said to have finished the year up more than 20% net of fees. Founded hedge fund from office above communist book store 1988. Today D.E. Shaw manages $39 billion across hedge fund, private equity, investment banking, insurance operations. Firm bought FAO Schwarz toy store out of bankruptcy in May. Sold 20% of equity in management company to Lehman Brothers last year; no longer involved in day-to-day operations. Solves scientific riddles as head of D. E. Shaw Research.